Red Sox manager John Farrell made the announcement earlier in the day and Lester then went out and threw four scoreless innings, giving up two hits with no walks with four strikeouts in a 4-1 loss to the Marlins.

“It’s been a real good spring for him,” said Farrell. “He’s been sharp. He’s been consistent. Today was no different. Multiple pitches for strikes. He’d had the benefit of pitching against this club previous so I think he had some understanding of their aggressiveness.

“And once again, very much in control. Made some quality pitches on the rare occasion when he did get behind in the count. But a very good spring for Jon.”

In six spring outings spanning 24 innings, Lester has allowed just two runs on eight hits and four walks with 20 strikeouts. With an ERA of 0.75, he said his spring could not have gone much better.

“It’s been great,” Lester said. “From not just a pitching aspect. I would say from just day one as far as PFPs, the meetings, to everything. It’s just been smooth. It’s been crisp. A lot of energy from the guys. It’s been a good spring all around, I think, for everybody.”

Slowey went five innings, giving up one run on five hits and three walks with four strikeouts. The lone run the right-hander allowed came on Jonny Gomes’ two-out home run in the second inning.

“Slowey looked good,” said Marlins manager Mike Redmond. “He gave us a good five innings. Mixed in a few breaking balls. I thought he was efficient.”

Slowey came into camp as a non-roster invitee and is now the Marlins’ No. 5 starter.

“I’m just very thankful for the opportunity I got,” he said. “I had plenty of opportunity. Without opportunity, there’s no success. For me, it’s going to be every five days going out there and giving my team a chance to win.”

Red Sox right-hander Daniel Bard, who is fighting for a bullpen spot after a disastrous attempt at starting last season, gave up three runs in the seventh. In eight spring appearances over eight innings, Bard has a 6.75 ERA.

“Frustrating,” Bard said. “I felt like I actually threw the ball pretty well. One thing I think I didn’t do well was throw my off-speed for strikes. That allowed them to sit on the fastball a bit. ... They were finding holes, I guess. Not going to dwell on it too much. Can’t get too wrapped up in results in spring training.”

Austin Kearns and Chris Valaika led off the seventh with consecutive singles, and Casey Kotchman’s groundout moved the runners to second and third before Koyie Hill’s sacrifice fly scored Kearns. With Wilson Valdez batting, a passed ball by catcher Jarrod Saltalamacchia moved Valaika to third. After Valdez walked, Daniel Pertusati’s double scored both runners, giving Miami a 3-1 lead.

The Marlins added two runs in the ninth off left-hander Ryan Rowland-Smith when Pertusati’s two-out single scored Valaika and Kotchman.

NOTES: The Marlins announced RHP Ricky Nolasco will start on Opening Day, followed by RHP Nathan Eovaldi, LHP Wade LeBlanc, HO Henderson Alvarez, and Slowey. It will be Nolasco’s second Opening Day start and first since 2009. ... Marlins 2B Donovan Solana, who has been sidelined for a week with a sore back, was scheduled to play in a minor league game Wednesday. ... Following Lester in Boston’s rotation will be RHP Clay Buchholz, RHP Ryan Dempster, LHP Felix Doubront and RHP John Lackey. ... C Ryan Lavarnway was optioned to Triple A and RHP Anthony Carter and RHP Jose De La Torre were reassigned to minor league camp. ... CF Jacoby Ellsbury (ankle, hell) and RF Shane Victorino (wrist) were out of Boston’s lineup with injuries. Both are expected to play Thursday. ... Red Sox DH David Ortiz took batting practice before the game, his first BP session since being shut down two weeks ago to rest his sore heels. ... SS Stephen Drew also took batting practice for the first time since suffering a concussion March 7 when he was hit in the helmet by a pitch.